Sökning: "Multiple antennas"

Visar resultat 31 - 35 av 150 avhandlingar innehållade orden Multiple antennas.

1. 31. Estimation and Performance Analysis of Wireless Multiple Antenna Communication Channels

   Författare :Mikael Coldrey; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; capacity; Wireless communications; performance bounds; distributed sources; generalized beamforming; channel estimation; MIMO; training;

   Sammanfattning : The focus of this thesis is on channel estimation in wireless communication systems that employ multiple antennas.The thesis is divided into two parts, whereof the first part addresses theproblem of parameter estimation of distributed sources. Due to, e.g. LÄS MER

3. 32. Study of Mutual Coupling in Finite Antenna Arrays for Massive MIMO Applications

   Författare :Tomislav Marinovic; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multiple scattering; Massive MIMO; mutual coupling MC ; 5G; iterative methods; base station antenna BSA ;

   Sammanfattning : This thesis focuses on the study of mutual coupling (MC) in finite antenna arrays for base station antennas (BSAs) for Massive multiple-input multiple-output (MIMO) applications, with an emphasis on the development of a computationally-efficient modeling technique for the analysis of MC which can be readily applied in the design or synthesis schemes for BSAs. Traditionally, the effects of MC have been ignored or underestimated in the analyses performed within the information-theoretic-based communities by assuming idealized antenna elements with no MC between them or by considering the fictitious isotropic radiator models. LÄS MER

4. 33. Channel Estimation and Prediction for 5G Applications

   Författare :Rikke Apelfröjd; Mikael Sternad; Emil Björnson; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Channel estimation; Channel prediction; Channel smoothing; Linear estimation; Kalman filter; Massive MIMO; Coordinated Multipoint transmission; Robust precoding; Predictor antennas; Limits of predictability; Long range predictions; Electrical Engineering with specialization in Signal Processing; Elektroteknik med inriktning mot signalbehandling;

   Sammanfattning : Accurate channel state information (CSI) is important for many candidate techniques of future wireless communication systems. However, acquiring CSI can sometimes be difficult, especially if the user equipment is mobile in which case the future channel realisations must be estimated/predicted. LÄS MER

5. 34. Design and Evaluation of Compact Multi-antennas for Efficient MIMO Communications

   Författare :Ruiyuan Tian; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antenna; propagation channel; MIMO system; wireless communication;

   Sammanfattning : The use of multi-antenna systems with multiple-input multiple-output (MIMO) technology will play a key role in providing high spectrum efficiency for next generation mobile communication systems. This thesis offers valuable insights on the design of compact multi-antennas for efficient MIMO communications. LÄS MER

7. 35. Modeling multiple antenna systems in realistic environments - a composite channel approach

   Författare :Fredrik Harrysson; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : For evaluation of specific antenna arrangements in wireless communication systems we need physical channel models that take into account the directional domain. Here we propose a practical approach to wireless channel modeling in, particularly, mobile communication systems, by using an assumption that the channel can be divided into separate parts or regions that can be treated and modeled individually. LÄS MER